1. Technical Field
The present invention relates to an embedded block humidifier for humidifying an embedded block having a biological specimen embedded in an embedding agent, an automatic thin slice manufacturing device for automatically manufacturing a thin slice by slicing the humidified embedded block, and an automatic thin slice specimen manufacturing apparatus for automatically manufacturing a thin slice specimen in which the manufactured thin slice is fixed onto a substrate.
2. Related Art
In the past, a toxicity test, a pathology test, or the like using a laboratory animal is carried out before a clinical trial for new drug development. Such test and experiment are carried out by using a thin slice specimen in which a thin slice having a thickness of several μm (for example, 3 to 5 μm) is fixed onto a plate such as a slide glass. The thin slice is obtained in such a manner that a laboratory animal such as a mouse or a rabbit receiving a drug is subjected to an autopsy and is sliced for the pathology test. Additionally, the thin slice is manufactured for each of various parts (for example, brain, lung, and the like).
A microtome is known as a device for manufacturing such thin slice specimen. Here, a general method of manufacturing a thin slice specimen using the microtome will be described.
First, moisture of a formalin-fixed biological specimen such as an organism or an animal is replaced with paraffin and again the periphery thereof is solidified by paraffin, thereby manufacturing an embedded block in a block shape. Subsequently, the embedded block is set at a microtome as a slicing device to be subjected to a roughing cut process. In terms of the roughing cut process, the surface of the embedded block becomes flat, and the surface of the embedded biological specimen as an experiment or observation object is exposed.
After the roughing cut process ends, a main cutting process starts. This main cutting process corresponds to a process in which the embedded block is cut into an ultra thin slice having the above-described thickness by a cutting blade of the microtome. Accordingly, it is possible to obtain the thin slice. At this time, since the embedded block is cut into the ultra thin slice as thin as possible, a thickness of the thin slice is approximately identical with a thickness of a cell level, thereby obtaining a thin slice specimen having higher quality. Accordingly, it is required to manufacture a thin slice having a smaller thickness. Additionally, the main cutting process is repeated until obtaining a necessary sheet of thin slice.
Subsequently, an extending process is carried out in which the thin slice obtained by the main cutting process is extended. That is, since the thin slice manufactured by the main cutting process is cut into the ultra thin slice, the thin slice is in a wrinkling state or a rounding state (for example, in a U-shape). For this reason, it is necessary to remove the wrinkling or rounding of the thin slice to be thereby extended in terms of the extending process.
In general, the extending process is carried out by the use of water and warm water. First, the thin slice obtained by the main cutting process is floated on water. Accordingly, it is possible to remove the wrinkling or rounding of the thin slice while preventing paraffin embedding the biological specimen from being adhered to each other. Subsequently, the thin slice is floated on warm water. Accordingly, since the thin slice is easily extended, it is possible to remove the remaining wrinkling or rounding not completely removed during the extending process using water.
Subsequently, the thin slice subjected to the extending process using warm water is lifted up by the use of a substrate such as a slide glass to be placed on the substrate. Additionally, when the extended degree is not sufficient at this time point, the substrate is heated by being placed on a hot plate or the like. Accordingly, it is possible to more extend the thin slice.
Finally, the substrate having the thin slice placed thereon is dried in a dryer. In terms of the drying process, moisture attached to the thin slice during the extending process evaporates and the thin slice is fixed onto the substrate. As a result, it is possible to manufacture the thin slice specimen.
Incidentally, when the surface of the embedded block is dry upon manufacturing the thin slice, a problem may arise in that wrinkle or deformation occurs in a slice surface. For this reason, it is necessary to carry out an operation in which the embedded block is prevented from being dried. That is, it is necessary to prevent the embedded block from being dried by appropriately humidifying the embedded block.
Therefore, as an example of embedded block humidifying devices, Patent Document 1 discloses an embedded block humidifying device in which misty droplet (hereinafter, referred to as mist) is generated in terms of ultrasonic vibration and an embedded block is humidified by the mist.    [Patent Document 1] JP-A-2004-28507
However, the humidifying device according to the related art still has a problem to be solved.
First, the embedded block will be simply described. In general, paraffin having a water repellent property is used as an embedding agent embedding a biological specimen. Additionally, since moisture of the biological specimen itself is replaced with paraffin, its surface has a water repellent property. Incidentally, as shown in FIG. 12, countless gaps S1 are formed in a surface of a biological specimen S in which moisture is replaced with paraffin. Accordingly, in order to humidify the embedded block, it is necessary to humidify the biological specimen S from the inside in terms of the countless gaps S1.
Incidentally, each of the countless gaps S1 corresponds to a minute gap having a diameter of several hundreds nm to 1 μm or so. For this reason, as shown in FIG. 13, even when mist M is generated and attached to the surface of the embedded block, in many cases, the mist M bounces on an entrance of the gap S1 due to the influence of surface tension. Accordingly, the mist M cannot easily enter into the gap S1, and hence it requires much time to allow the mist M to enter thereinto.
Meanwhile, when an amount of mist increases in order to reduce a time necessary for the humidification, another problem arises. That is, in a case where the amount of mist increases, an excessive amount of mist M is attached to the surface of the embedded block. Then, the surface temperature of the embedded block reduces by 2° C. or so due to evaporative latent heat generated when an excessive amount of mist M evaporates, thereby causing a problem in that thermal contraction occurs in the embedded block. As a result, a problem arises in that a deviation in thickness of the thin slice obtained by slicing the embedded block occurs.